Hi 



Issued December 17, 1912. 

U. S. DEPARTMENT OF AGRICULTURE. 
BUREAU OF PLANT INDUSTRY — BULLETIN NO. 262. 

B. T. GALLOWAY, Chief of Bureau. 



ORNAMENTAL CACTI: 

THEIR CULTURE AND DECORATIVE VALUE. 



v HARLES HENRY THOMPSON, 
Assistant Botanist, Missouri Botanical Garden. 




\\ \ >■ KINGTON: 
GOVERNMENT PRINTING OFFICE. 
1912. 



Class ST 3 ) 4)^> 
Book_iCrgJ!L 



ft 



Issued December 17, 1912. 

U. S. DEPARTMENT OF AGRICULTURE. 
BUREAU OF PLANT INDUSTRY — BULLETIN NO. 262. 

B. T. GALLOWAY, Chief of Bureau. 



UUX 

ORNAMENTAL CACTI: ^° 

THEIR CULTURE AND DECORATIVE VALUE. 



BY 



CHARLES HENRY THOMPSON, 
Assistant Botanist, Missouri Botanical Garden. 




WASHINGTON: 
GOVERNMENT PRINTING OFFICE. 
1012. 




BUREAU OF PLANT INDUSTRY. 



Chief of Bureau, Beverly T. Galloway. 
Assistant Chief of Bureau, William A. Taylor. 
Editor, J. E. Rockwell. 
Chief Clerk, James E. Jones. 



Office of Farm Management. 

scientific staff. 

W. J. Spillman, Agriculturist in Charge. 
D. A. Brodie, C. B. Smith, J. C. McDowell, C. L. Goodrich, J. W. Froley, David Griffiths, Byron Hunter, 
E. H. Thomson, James M. Johnson, J. S. Cotton, J. H. Arnold, G. A. Billings, Levi Chubbuck, H. R. 
Cox, M. A. Crosby, L. G. Dodge; J. A. Drake, A. D. McNair, H. A. Miller, A. G. Smith, and E. O. 
Wooton, Agriculturists. 

3. S. Cates, L. W. Fluharty, C. E. Hoke, H. B. McClure, H. H. Mov-ry, F. D. Stevens, and D. W. Working, 

Assistant Agriculturists. 

J. S. Ball, C. M. Bennett, Lillian Church, L. G. Connor, H. M. Dixon, W. C. Funk, H. N. Humphrey, 
W. R. Humphries, Oscar Juve, G. H. Miller, H. B. Munger, E. A. Stanford, and M. J. Thompson, 

Scientific Assistants. 

O. H. Benson, C. M. Hennis, A. B. Ross, H. G. Smith, and S. M. Tracy, Agents. 
Iiena M. Bailey and Harry Thompson, Experts. 
Charles Henry Thompson, Collaborator. 



Horticultural Investigations and Arlington Farm. 

scientific staff. 

L. C. Corbett, Horticulturist in Charge. 
W. W. Tracy, sr. , Superintendent, Vegetable- Testing Gardens. 
E. C. Butterfield, Superintendent, Arlington Experimental Farm. 
W. R. Beattie, Assistant Horticulturist. 

N. H. Grubb, D. N. Shoemaker, and William Stuart, Experts. 
W. V. Shear, Assistant. 

262 " „ li- 

2 ft % 

IAN ,8 1913 



ADDITIONAL COPIES of this publication 
A may be procured from the Superintend- 
ent of Documents, Government Printing 
Office, Washington, D. C, at 15 cents per copy 



LETTER OF TRANSMITTAL 



U. S. Department of Agriculture, 

Bureau of Plant Industry, 

Office of the Chief, 
Washington, D. C, July 9, 1912. 
Sir: I transmit herewith and recommend for publication as Bulle- 
tin No. 262 of this Bureau an illustrated manuscript entitled 11 Orna- 
mental Cacti: Their Culture and Decorative Value." This manu- 
script was prepared by Mr. Charles Henry Thompson, who carried 
on the investigations under the direction of the Agriculturist in 
Charge of Cactus Investigations in the Office of Farm Management. 
Owing to its strictly horticultural nature, it was deemed wise that it 
be issued from the Office of Horticultural Investigations and Arling-, 
ton Farm. 

Mr. Thompson has long been in charge of the Succulent Collections 
of the Missouri Botanical Garden, St. Louis. His position and 
experience eminently qualify him to discuss this subject. 

It is believed that while this bulletin may be of interest to cactus 
fanciers throughout the country, its particular field of usefulness' 
will prove to be the warmer and drier southwestern regions where 
these plants are extensively used for decorative gardening. 
Respectfully, 

B. T. Galloway, 

Chief of Bureau. 

Hon. James Wilson, 

Secretary of Agriculture. 

262 

3 



CONTENTS. 



Page. 



Introduction 7 

Propagation of cacti from seeds 8 

Vegetative propagation 11 

Grafting , 12 

Culture.. 13 

Diseases 15 

Insect pests 16 

Economic value of cacti 16 

Medicines 16 

Garden vegetable 16 

Fruits 17 

Wood 17 

Hedges 18 

Decorative value of cacti t 18 

Single plant displays 20 

Groupings . 21 

Plantings in open ground 21 

Cultivated forms of cacti . 22 

262 



5 



ILLUSTRATIONS. 



Page. 



Plate I. Mamillaria cornifera, Missouri Botanical Garden, St. Louis, 1899 12 

II. Fig. 1. — Mamillaria compacta, Missouri Botanical Garden, St. Louis, 
1911. Fig. 2. — Mamillaria pyrrhocephala, Missouri Botanical 
Garden, St. Louis, 1910 12 

III. Echinopsis calochlora, Missouri Botanical Garden, St. Louis, 1907.. 14 

IV. Opuntia leucotricha, natural landscape at Durango, Mexico, 1909. . . 14 
V. Fig. 1. — Opuntia leucotricha, A. S. White Park, Riverside, Cal., 1909. 

Fig. 2. — Opuntia microdasys, A. S. White Park, Riverside, Cal., 

1909 16 

VI. Cereus marginatus used as a hedge plant, Encarnacion, Jalisco, 

Mexico 16 

VII. Cereus tortuosus, Missouri Botanical Garden, St. Louis, 1898 16 

VIII. Cereus eburneus, Missouri Botanical Garden, St. Louis, 1905 16 | 

IX. Pilocereus polylophus (Cereus nickelsii), Missouri Botanical Garden, 

St. Louis, 1905 16 

X. Echinopsis gemmata, Missouri Botanical Garden, St. Louis, 1898 16 

XI. Cereus weberi predominating in natural landscape at Tomellin, 

Mexico, 1909 20 

XII. Cereus stellatus (in foreground), natural landscape, at Tomellin, 

Mexico, 1909 20 

XIII. Fig. 1. — Pilocereus fulviceps, Tehuacan, Mexico, 1910. Fig. 2.— 

Cereus eburneus, Tomellin, Mexico, 1910 20 

XIV. Ornamental planting of cacti, Missouri Botanical Garden, St. Louis. . 20 
XV. Mamillarias planted in formal design, Missouri Botanical Garden, 

St. Louis, 1905 22 

XVI. Cactus garden, A. S. White Park, Riverside, Cal., 1905 22 

XVII. Succulent rockery in Alamo Park, San Antonio, Tex., 1904 22 

XVIII. Echinocactus ingens, Tehuacan, Mexico, 1905 22 

262 
6 



B. P. I.-768. 





ORNAMENTAL CACTI: THEIR CULTURE AND 
DECORATIVE VALUE, 



With the exception of a few species of Rhipsalis the cacti are 
strictly indigenous to the Western Hemisphere. The introduction 
of these plants into Europe evidently began soon after the discovery 
of America. The English, Dutch, and Spanish traders, who early 
carried on a commercial business in the West Indies, South America, 
Central America, and Mexico, took back to their respective countries 
many interesting and curious plants then new to the gardens and 
plant lovers of Europe. 

In the earliest published reports of the introduced and cultivated 
plants of European gardens we frequently find accounts and in many 
instances illustrations of cacti. Gradually additional plants were 
introduced, until at the time Linnaeus published his Species Plantarum 
(1753) he recognized 22 species, all of which he included under the 
generic name of Cactus. They were commonly known as thistles, 
probably from the spiny character of their protective armor. The 
smaller, more or less globose forms, were called "melon" thistles, 
while the taller ones were called "torch " thistles or "candle" thistles. 
The Ficus indica, or Indian fig, and several other species of Opuntia 
were introduced into the Mediterranean region at a very early date. 

From the time of the publication by Linnaeus the steady introduc- 
tion of new plants was continued from the Western Hemisphere into 
Europe. These importations included many forms of cacti. Miller, 
in his dictionary, enumerates a number of species distinct from 
those recognized by Linnaeus. Others were described and published 
from time to time by Haworth, Link and Otto, Salm-Dyck, P. 
De Candolle, Lemaire, Pfeiffer, and others. The most extensive 
modern systematic work is Gesammtbeschreibung der Kakteen, by 
Dr. Karl Schumann. 

It was not until within the past half century that any special 
interest in cacti was manifested in America. A few species, such as 
the night-blooming cereus (Cereus grandiflorus and Cereus nycticalus), 
queen of the night (PJiyllocactus acuminatus), crab cactus (Epiphyl- 
lum truncatum), and the rat-tail cactus {Cereus flagelliformis), had 
become favorites as house plants. General collections of this group of 
262 7 




INTRODUCTION. 



8 



ORNAMENTAL CACTI. 



the plant world by Dr. George Engelmann laid the foundation for 
the large collection at the Missouri Botanical Garden at St. Louis, 
Mo. Similar interest manifested by Dr. Asa Gray added mate- 
rially to the collection at the Botanical Garden at Cambridge, Mass. 
As the public became more acquainted with these bizarre forms 
of vegetation, a livelier interest in them sprang up, and many persons 
throughout the country began to gather private collections. Fan- 
ciers became so numerous that in certain localities clubs or societies 
were organized among them, where ideas and experiences as to the 
culture of these plants could be discussed and specimens exchanged. 
Experience was the high-priced teacher from whom these collectors 
had to gain their knowledge. Similar organizations were formed in 
Germany, where amateur collectors were numerous, and also in 
France and in England. Many articles have been published in the 
horticultural journals of these countries describing proper methods 
of propagation and culture, and Mr. Watson, of the Kew Gardens, 
England, issued a Handbook of Cactus Culture. These helps have 
disseminated a better general knowledge of methods to be employed, 
but the soil and climatic conditions of Europe differ so materially from 
those of various parts of America that their rules are not well adapted 
to our own special needs. 

The growing interest in this group of plants in America and the 
inadaptability of rules for general gardening in growing them, as 
well as of rules laid down for their special care by European growers, 
have created a demand in this country for a work that will include 
both general and special rules that may be applied to any part of 
our country. To meet this demand is the writer's purpose in putting 
forth this bulletin. Naturally, much of the material herein con- 
tained is compiled from the experiences of others, but use of it is made 
only in so far as it agrees with the writer's experience and obser- 
vations, gained during the years spent in caring for the collection 
at the Missouri Botanical Garden and in traveling through the native 
haunts of these plants throughout the Southwestern States and in 
Mexico, as well as in the examination of many private collections. 

PROPAGATION OF CACTI FROM SEEDS. 

Most cacti yield seeds abundantly. Ordinarily, few of these seeds 
germinate and develop into mature' plants, because of unfavorable 
environment. The seeds are usually fertile, however, and when 
planted under proper conditions a large percentage of them will 
germinate and with a little care will produce plants in abundance. 

The best soil for growing cacti from seed has proved to be a thor- 
oughly decomposed sod mixed with at least its own volume of sand. 
After these ingredients have been carefully mixed, they are run 

262 



PROPAGATION OF CACTI FROM SEEDS. 



9 



through a sieve of about J-iiich mesh, which removes any large 
particles and all superfluous root fibers, making a loose soil which 
drains very readily. It is not necessary that the soil be very rich in 
humus, and manured soils should always be avoided because of their 
undue tendency to hold moisture. They are also a medium for 
producing germs of decay. An open, drahiable soil is the chief 
requisite for cultivating cacti. 

For germinating the seeds an ordinary 4-inch pot is very con- 
venient. New pots are preferable, but old pots may be used with 
safety if thoroughly sterilized. Porous pots are soon covered with 
green algae when left in a moist place for any considerable time. This 
growth will spread over the surface of the soil in a close blanket which 
precludes the free access of air and seriously retards the drainage of 
superfluous water. These algae will in time grow over the little 
seedlings that have survived other adverse conditions and will 
smother them to death. To combat the algae the pots should be 
thoroughly sterilized just previous to being used, and to accomplish 
this object two efficient methods have been found. One method is to 
bake or burn the pots, so that all life on them or in their pores may be 
destroyed. The other method is to soak the pots for a time in a weak 
solution of copper sulphate and then thoroughly wash them in the 
same solution. If a very strong solution of the copper sulphate is 
used, some of it will be left in the pores of the clay, and later, when the 
seedlings are being watered, enough may pass through the soil to 
injure the tender young plants. 

Reasonable care should be exercised in preparing the pot for plant- 
ing. As a rule the drain hole in the bottom of the pot is too small and 
is easily clogged. This hole should be enlarged, as thorough drainage 
must be maintained in growing cacti. The pot should be filled to 
one-fourth its depth with small bits of broken pots, and on these the 
prepared soil should be placed and pressed or shaken together firmly 
but not packed hard. The soil surface is then leveled by the use 
of a round, flat-faced tamper of a diameter to just fill the pot. 
The soil should not be packed but should be lightly tamped, 
with only sufficient effort to produce a smooth, level surface. This 
surface should be about half an inch from the top of the pot. Over 
it the seeds are evenly distributed and then covered with a very thin 
layer of soil, upon which is spread a layer of fine gravel to a depth of 
about one-fourth of an inch. This layer of gravel is important in 
many ways. As the pots are later watered with a fine spray, it 
prevents the surface of the soil from washing and consequently keeps 
the seeds from being disarranged. It also promotes the free passage 
of moist air through the spaces between the bits of gravel, which, 
together with the shading by the gravel, prevents the surface of the 
56603°— Bull. 262—12 2 



10 



ORNAMENTAL CACTI. 



soil from becoming dry and baked. It also checks the growth of 
algae over the soil surface. 

As the seedlings grow they easily force their way through the gravel 
to the sunlight. For the first few months of their existence, cactus 
seedlings are but small, globular, balloon-shaped or cylindrical bodies, 
composed of very thin-walled cells filled to turgidity with water. 
They are so tender and delicate that they readily "damp off" if 
subjected to a sudden change from a high to a low temperature. The 
death rate of seedlings from this cause has-been greatly minimized or 
almost wholly checked by the use of the gravel over the surface of 
the soil. This layer, with its intervening spaces, acts as a protection 
from sudden changes in temperature during that period of their 
growth when the seedlings are most susceptible to injury. By the 
time they have grown sufficiently large to project beyond the gravel 
they have become hardier and more robust in structure. Again, the 
gravel layer is of great value in that it keeps the surface of the soil 
moist. The little seedlings have exceedingly fine and delicate roots 
which spread out near the surface of the soil. If this surface is 
allowed to dry out to the depth of one-eighth of an inch or more, these 
delicate rootlets will be destroyed and the seedlings will be damaged 
or killed. In most instances the diminutive plant has not enough 
food stored up in its body to keep it alive until another set of feeding 
roots can be produced, and it starves to death. For watering, a vessel 
should be used that gives a fine, gentle spray, in order to avoid the 
danger of washing the seeds from their position or of injuring the 
delicate young seedlings. Watering should be done at least once a day. 
The temperature of the propagating house or frame should be kept 
as nearly uniform as possible and should not vary much from 70° F. 

The proper time for transplanting the seedlings differs for different 
genera and species, but they should usually be left in the germination 
pot until the plant shows at least three or four clusters of spines. By 
that time the tissues will have become considerably hardened and a 
very good root system will have been formed. The taller growing 
species, such as Cereus, will be the first ones ready for transplanting. 
Mamillaria and kindred genera and plants of similar growth will be 
the last. The seedlings should be transplanted into a flat sufficiently 
small for convenient handling, which should be provided with drain- 
age openings in the bottom. It should be filled with the same kind 
of material and soil as used in the germination pots, the surface to 
be carefully leveled in the same way. The rows should be about an 
inch apart, with the same interval between seedlings in the row. 
After the flat has been filled with the seedlings a thin layer of clean 
gravel should be placed all over the soil surface and close up around 
the plants. The flats should then be placed in a perfectly level posi- 

262 



VEGETATIVE PROPAGATION. 



11 



tion, so that the soil will not shift from one side toward the other 
when watered. Cactus plants are of slow growth and may remain in 
the flat for several months before being potted. The proper time for 
potting is when the plants have grown so large that they begin to 
crowd each other or when the roots of adjacent plants begin to 
intermingle. In preparing pots for individual plants the same method 
should be followed as for the preparation of the germination pots, 
except that a coarse soil may be used to advantage. It is not advis- 
able to begin with pots smaller than 2h inches, as they dry out too 
rapidly. 

VEGETATIVE PROPAGATION. 

Almost all cacti may be readily propagated from cuttings. The 
plants are so soft in tissue and so filled with water that any bruise 
or mutilation is likely to be the point of attack of a rot fungus, which 
quickly destroys them; so, in making the cutting, a clean, sharp 
knife must be used and a smooth surface left on the cut end. The 
cutting should then be placed in a dry atmosphere for a day or 
more, until, by drying, a kind of cuticle has formed over the cut sur- 
face. The cutting may then be rooted in sand on a bench or planted 
directly in pots. In the warmer, drier regions it may be placed 
directly in the open ground, provided the soil has perfect drainage. 
In greenhouse culture it is best not to place much of the cutting 
below the surface of the soil or sand; 1 inch is sufficient for large 
plants, and less than that for smaller ones, in proportion to the 
size of the cutting. When the cutting is long and likely to fall 
over, a stick should be inserted in the soil by its side and the two 
securely tied together until roots have been formed. When mature 
plants are shipped in from the field the roots are always more or 
less injured. It is always best to cut away the roots, let the wounds 
dry and heal for a time, and then plant them as cuttings. Many 
of the opuntias are naturally adapted to propagate themselves 
vegetatively. The stems are readily detached at the joints. These 
stems fall to the ground and in a short time develop roots and begin 
to grow as independent plants. Some are adapted for even wider 
dissemination. The spines which they bear are very sharp and 
stiff, and are barbed. These spines penetrate the skins of passing 
animals and cling so tenaciously that the joints bearing them are 
readily detached from the parent plant and may be carried a con- 
siderable distance before being released from their carrier. Once 
lodged in proper soil under favorable climatic conditions, they soon 
become new individual plants. In many of the opuntias the fruits 
are sterile but proliferous. They may be removed and treated as 
cuttings and will readily produce new plants. Many of the smaller 
forms, such as Echinocactus, Echinocereus, and Mamillaria, pro- 

262 



12 



ORNAMENTAL CACTI. 



1 



duce branches (PL I) which are readily detachable and are easily 
rooted as cuttings. Some species of Mamillaria have side shoots 
winch are so lightly attached that they break off by a slight touch. 
Such plants depend almost entirely on vegetative propagation and 
rarely produce flowers and fruit. 

GRAFTING. 

Grafting is easily accomplished throughout this whole group of 
plants. The possibilities of uniting both species and genera seem 
to be unlimited. For a long time it has been a practice to graft 
Epiphyllum on Peireskia or some upright, stiff-stemmed Cereus in 
order to produce a more decorative bush plant. The rat-tail cactus 
{Cereus fiagelliformis) is frequently treated in the same manner. 
Aside from its ornamental possibilities, grafting may be resorted to 
profitably as a means of propagation. It not infrequently happens 
that a plant becomes decayed at its base, and when all evidence 
of decay or disease has been removed there will be so little healthy 
tissue left that it is next to impossible to get it to grow as a cutting. 
Such a piece may be grafted on a healthy stock and the plant be 
preserved, if the growing tip is intact. A cleft graft or a saddle 
graft is more desirable where either of these can be employed, since 
they require less work in preparation and give a good large surface 
for the union of the tissues. The mucilaginous sap that exudes 
from the cut surface of a cactus plant allows the stock and scion 
to slip apart very easily, and the parts become disarranged unless 
proper precaution is used to prevent it. For this purpose the needle- 
like spines of Peireskia or Opuntia may be used. The two parts are 
pressed firmly together into the desired position, and then a spine 
is thrust through the united portions, securely pinning them in that 
position. No wax is required, but it is best to closely wrap the 
graft with raffia to exclude the air. The grafted plants are then 
placed in a warm, moderately moist jilace until the tissues have 
become thoroughly knitted together. They should not be placed 
where they might be subject to drying, for under such conditions 
the cut surface will be the first to dry, and consequently a perfect 
union will be prevented. 

\Yith small globose or thick plants, such as Mamillaria (PI. II), 
Echinocactus, Echinocereus, etc., a different method is preferable. 
The head of the plant is cut away with a perfectly smooth trans- 
verse cut. (PI. III.) A stock is selected which has about the 
same diameter as the scion, and it is also given a smooth transverse 
cut. The two flat surfaces are then pressed firmly together and 
held in place by tying them together with a cotton or other soft 
cord. It is quite essential that clean instruments be used to prevent 

262 



Bui. 262, Bureau of Plant Industry, U. S. Dept. of Agriculture. 



Plate I. 




Mamillaria Cornifera, Missouri Botanical Garden, St. Louis, 1899. 




Fig. 2.— Mamillaria Pyrrhocephala, Missouri Botanical Garden, St. Louis, 1910. 



CULTURE. 



13 



the inoculation of the plant with disease germs. A number of the 
upright-growing species of Cereus have been used successfully for 
stocks, and there seems to be no limit to the number of species 
that may be used. It has been found, however, that some are. 
better than others for the purpose. When it is desired to have 
the scion a foot or more high, good stocks may be obtained from 
Cereus stellatus, C. serpentinus, and other species of similar habits 
of growth. These stocks are preferable for use in grafting Cereus 
jlagelliformis and species of Epiphyllum and Rhipsalis, which nor- 
mally grow in a pendent position. Where only short stocks are 
desired the above may be used, and also Cereus nycticalus, C. tor- 
tuosus, C. bomplandii, C. macdonaldiae, and C. grandijiorus. These 
latter plants are weak stemmed when allowed to grow tall; hence, 
they can not be used for high grafts unless supported by a stake of 
some kind. All these species are readily grown from cuttings, 
which should be somewhat longer than the stock is to be. When 
the cutting is thoroughly rooted it should be potted and kept in 
good growing condition until a new root system has formed. It will 
then be ready to receive the scion after having been cut back to the 
desired height. 

CULTURE. 

Cacti thrive from southern Canada to far down in South America. 
Between these extreme points there is scarcely any combination of 
atmospheric and soil conditions that does not support one or more 
species of the family. They are found near the seashore in the 
Tropics, as well as high up on the mountains, where in winter they 
are subjected to severe frosts. They are most abundant, however, 
in the higher serniarid tablelands. With these facts in mind, it is 
clear that when collected they can not all be treated alike, but must 
be grouped according to the conditions under which the individuals 
grow in their native haunts, and each group must receive a different 
treatment to accord therewith. 

Epiphyllum, Rhipsalis, a few species of Phyllocactus, and some 
species of Cereus are epiphytic in their tropical homes and should be 
given like treatment in conservatories. They should be grown under 
practically the same warm, moist atmospheric conditions as are 
tropical orchids, which may be grown in baskets of peat and moss, 
or be trained on blocks or stumps, or on walls, wherever the roots 
have opportunity to penetrate a moisture-laden medium. Most 
species of Phyllocactus and of the climbing species of Cereus should 
be grown in orchidlike conditions of temperature and humidity but 
in very loose, moderately rich soil. For this purpose a mixture of 
loam, sand, and an abundance of thoroughly decomposed leaf mold 
makes an excellent soil. By far the greater number of species of 

262 



14 



ORNAMENTAL CACTI. 



cacti are terrestrial in their habits and are indigenous to warm, semi- 
arid regions. The annual rainfall in these regions is very slight and 
continues for only a brief period. It is difficult to reproduce such 
conditions in our northern climate, and it is found that cacti can best 
be grown here by minimizing the action of our abundant rains by 
having the plants placed in a thoroughly well-drained situation. It 
is equally difficult to reproduce the conditions in our conservatories* 
where they are heated artificially, because of the drying effect of the 
heat. This condition may be largely counteracted by a judicious 
watering of the soil about the plants. For this group of plants it is 
not necessary that the soil be very rich, but it is essential that it be 
very open and thoroughly drained. 

In repotting older plants it is best to disturb the roots as little as 
possible. Enlarge the drain opening in the bottom of the pot and 
place over it broken pots or other coarse material to not less than 1 
inch in depth, to insure perfect, uniform drainage. Over the coarse 
material put a layer of soil. Remove the plant to be repotted by 
inverting the pot and gently tapping its rim on the edge of a bench 
or some such solid structure. The whole body of dirt will come out 
in a lump. Remove any bits of broken pots that may be attached to 
the bottom, but leave the soil in place about the roots. The surface 
soil should be removed if it shows any evidence of containing algse or 
fungous growths. Place this ball of dirt and roots in the next pot 
and pack fresh soil about it, leaving sufficient space at the top to 
receive water. In conservatories pots are apt to become coated 
with green algae, and old pots especially so, because the spores of the 
alga3 are likely to remain in the pores of a pot from its previous use. 
Old pots should be thoroughly sterilized, as heretofore explained for 
the germination pots. After the plant is potted the surface of the 
soil should be covered with fine gravel to a depth of ajt least half an 
inch. 

The soil about the plants should never be allowed to become abso- 
lutely dry for any great length of time or the roots will be seriously 
injured; on the other hand, it must not be kept saturated, but 
should be kept moist at all times. Any superfluous water standing 
about the base of the plant or in the soil about its roots is a serious 
menace, since it acts as a medium through which germs of rot enter 
the plant and soon destroy it. Cactus plants contain so much liquid 
that decay works very rapidly through them. When decay is once 
started it is difficult to save the plant ; hence, the urgent necessity for 
having thorough drainage below the plant and a thoroughly drain- 
able soil. Failures in the growing of cacti are undoubtedly due more 
to the neglect of this precaution than to all other causes combined. 

Cacti do not require to be pruned beyond the removal of dead por- 
tions and to keep the plants in shape within the space allotted to 

262 



Bui. 262, Bureau of Plant Industry, U. S. Dept. of Agriculture. 



Plate III. 




Bui. 262, Bureau of Plant Industry, U. S. Dept. of Agriculture. 



Plate IV. 




DISEASES. 



15 



them. Pruning may be done at any time, but preferably when the 
atmosphere is dry, so that the cut surface may dry and heal quickly. 

In conservatories during the colder season, in order that the air 
may be sufficiently dry, a temperature ranging from 60° to 70° F. 
should be maintained. A temperature lower than 60° for any con- 
siderable length of time would hold the moisture about the plants too 
long and invite decay. During the warmer season, if the plants are 
kept in the house it is necessary that it be kept fully ventilated. 
The aim is to have at all times a dry atmosphere and a moderately 
moist well-drained soil. If the plants are placed in open ground during 
the summer months and their pots plunged in the beds, these beds 
likewise must be thoroughly drained. In placing a collection out of 
doors as a permanent planting, a situation should be selected, if 
possible, where the ground slopes sufficiently to insure perfect drain- 
age. If natural drainage is impossible, a system of drain tiles should 
be placed throughout the area to be planted and the soil above the 
tiles should be made loose and porous by the abundant addition of 
gravel and sand. Out-of-door planting is preferably done during 
the dry season, so that the cut surfaces or any injured portions of the 
plants will dry over quickly and be less easily infected with rot. 

DISEASES. 

The one disease from which cacti suffer more than any other is 
rot. The plant body is so saturated with water that it forms an 
excellent medium for the growth of this disease. It is liable to attack 
the plant at any point where the germs have opportunity to reach 
the interior. Any cut or bruised place presents the most favorable 
point for infection, from which the disease rapidly spreads and 
destroys the plant. Water dripping on a plant for even a short 
time may induce infection. By far the greater number of plants 
receive the infection through their bases or roots, whence it works 
upward through the center of the plant. By the time it has reached 
the surface the plants are usually too far gone to be saved. If the 
disease is detected before it has reached the crowns of the plants, 
they may be saved by cutting away all the diseased portions and 
then grafting the crowns dn some healthy stock. Otherwise, it is 
best to remove the plants at once and burn them. The soil in which 
they were potted and also the pots, if to be used again, should be 
sterilized, so that other plants may not be infected from them. 

Another disease more common to species of Marnillaria and to a 
less extent found on Echinocactus and Cereus makes its first appear- 
ance as a small, light orange-colored spot on any portion of the plant 
surface, usually starting at a pulvinus, which seems to be the point 
at which the infecting germ enters. This spot steadily grows until 

262 



16 



ORNAMENTAL CACTI. 



the plant is totally destroyed. The disease travels inward, toward 
the center of the plant, following fibrovascular bundles. The colored 
tissue readily separates from the healthier portion of the plant and 
is easily removed, but this merely checks its ravages for a time. The 
disease penetrates every portion of the plant and in time will make 
itself manifest again in other orange-colored spots on the surface. 
It is a contagious disease, and the only hope for saving a collection 
of plants is to destroy all the infected individuals, preferably by 
burning them. Many remedies for this disease have been applied, 
but without success. 

INSECT PESTS. 

The Bureau of Entomology of this Department has investigated 
cactus insects extensively. The results of this work appear in a 
bulletin of that Bureau (No. 113), which may be had upon appli- 
cation. 

ECONOMIC VALUE OF CACTI. 

MEDICINES. 

To a limited extent Cereus grandiflorus and C. nycticalus have 
been used in the preparation of certain compounds. Other 
cacti are known to contain characteristic alkaloids which from 
their peculiar action on the human s} 7 stem may yet prove of value 
in treating special disorders. Most notable of these forms is the 
so-called piote bean or mescal button, also known as the dumpling 
cactus (Lopliophora williamsii and L. lewinii). Since remote 
times the aborigines of America have used this plant in certain of 
their religious rites. When the plants are eaten raw, dried or fresh, 
with water, the optic nerve is so affected that by closing the eyes the 
user is made to see visions illuminated in the brightest of colors. 
An alkaloid of this plant has been separated from it and found to 
contain the same properties. It is not impossible that in time it may 
be found of value in the treatment of certain ocular disorders. How- 
ever, no member of the family seems as yet to have yielded a drug 
that has been used to any considerable extent as a medicine'. 

GARDEN VEGETABLE. 

Among the poorer classes of Mexico the very tender growths of 
Opuntia are eaten raw, made into a sort of salad, or are cooked, as 
may be desired. There is little to commend this cactus to those 
having access to the common and more palatable vegetables of the 
garden. 

262 



Bui. 262, Bureau of Plant Industry, U. S. Dept. of Agriculture. 



Plate V. 




Fig. 2.— Opuntia Microdasys (in foreground), A. S. White Park, Riverside, 

Cal., 1909. 



Bui. 262, Bureau of Plant Industry, U. S. Dept. of Agriculture. 



Plate VI. 




Bui. 262, Bureau of Plant Industry, U. S. Dept. of Agriculture. 



Plate VII. 




Cereus Tortuosus, Missouri Botanical Garden, St. Louis, 1898. 




Cereus Eburneus, Missouri Botanical Garden, St. Louis, 1905. 



Bui. 262, Bureau of Plant Industry, U. S. Dept. of Agriculture. 



Plate IX. 




PlLOCEREUS POLYLOPHUS (CEREUS NlCKELSIl), MISSOURI BOTANICAL GARDEN, 

St. Louis, 1 905. 



(Natural size.) 



Bui. 262, Bureau of Plant Industry, U. S. Dept. of Agriculture. 



Plate X. 




Echinopsis Gemmata, Missouri Botanical Garden, St. Louis, 1898. 



ECONOMIC VALUE OF CACTI. 



17 



FRUITS. 

The fruits of a great many species of cacti are very agreeable to 
the taste, as well as refreshing and nourishing. This is especially 
true of many species of Opuntia known as tunas. (Pis. IV and V.) 
In certain parts of Mexico the tuna forms a considerable part of 
the diet of the poorer natives. In many places it is grown for the 
market and finds ready sale among all classes. The outer part is 
peeled away in the same manner as in paring an apple or peach for 
consumption raw. The inner pulp, containing the seeds, not only 
possesses a pleasant flavor, but it also creates the impression of being 
cool even in the hottest weather. Forms of tuna have as wide a 
range in color, flavor, and size as many of our northern fruits. 

Numerous smaller fruits are gathered from wild plants, either for 
home consumption or for sale in the market. Among these may be 
mentioned the small, globose, red fruit of Cereus geometrizans and 
kindred species, which is very sweet. It is called " garambullo " by the 
Mexicans. A number of species of Mamillaria produce an abundance 
of smaller club-shaped red fruits which have a very pleasant, sweet 
taste, combined with a slightly acid tang, and are eaten by the na- 
tives, who call them " chilitos." The above-mentioned fruits, and also 
that of Cereus giganteus, are quite commonly used in the preparation 
of preserves, jams, and cakes of somewhat jellylike consistency. 
These preparations represent some of the choice delicacies of the 
natives and are to be found on sale in the markets and on the streets 
of Mexican cities. The fleshy interior of certain species of Echino- 
cactus is used in the production of the so-called cactus candy. The 
flesh is cut into layers and cured in sugar sirup and allowed to dry, 
similar to the manner in which citron is prepared for market. The 
cactus flesh merely forms a foundation, adding perhaps a little flavor. 

WOOD. 

For the most part all cactus plants are composed of soft, water- 
laden tissue, but the axis of the plant is composed of a woody core, 
which in some species makes a considerable development, especially 
in Opuntia and the large species of Cereus. This woody portion is 
always more or less porous and usually of an open, lacelike structure, 
so that it is of little value as compared with other woods. Neverthe- 
less, it is used to some extent in the manufacture of ornaments and 
rustic work, but more for its curious structure than for any real value 
the wood may possess. Some of the cylindrical forms of Opuntia 
yield rather grotesque and ornamental walking canes, as do also a 
few of the slender-growing columnar species of Cereus. These forms 

262 



18 



ORNAMENTAL CACTI. 



also furnish wood for rustic picture frames, ornamental pincushions, 
trays, inkwell stands, and the like. To a limited extent the wood of 
the taller growing species forms material in the shape of poles for the 
construction of fences and temporary huts. 

HEDGES. 

Because of their animal-resisting armor of spines, combined with 
their habit of growth, certain species of cacti are naturally adapted 
for use as efficient hedge plants wherever they grow in the open 
throughout the year. The one species most commonly used in Mex- 
ico for this purpose is the organo {Cereus marginatus) , PL VI, so 
called because of its fancied resemblance to the pipe of an organ. It 
branches freely from the base near the surface of the ground, and these 
branches immediately assume an upright habit of growth. Growing 
closely together they soon produce an impenetrable barrier. Its 
habits of growth recommend it, since there are scarcely any branches 
above the base and these never spread and cover any great area, 
thus making a compact, dense, and comparatively narrow hedge. 
Cereus stellatus and C. weberi are also used in the regions where they 
are abundant as native plants, but they have the disadvantage of 
making a thicker and more open hedge and consequently cover more 
ground. Where narrowness of the hedge is of minor importance, 
many of the taller growing species of Opuntia make an equally 
serviceable barrier and are at all times decorative, especially when 
bearing an abundance of flowers and fruits. 

DE COH ATI VE VALUE OF CACTI. 

It is not intended to convey the idea that cacti, as a whole, can 
hope to rival many other groups of plants in gorgeous display. For 
the most part they lack the foliage that lends so much to the value 
of other plants, and in most instances the flowers, when present, are 
either too small, too few (Pis. VII, VIII, IX, and X), or too short 
lived to be considered of any great worth. In some of the climbing 
species of Cereus and in Phyllocactus the flowers attain a very con- 
siderable size, and their waxlike texture and pure whiteness or deli- 
cately tinted red, pink, or cream colors present a combination that 
always calls forth exclamations of wonder and pleasant surprise. 
Many forms bloom at night, and their flowers are always white and 
to a slight degree pleasantly fragrant. The flowers are usually pro- 
duced in periods, each period lasting from one to three or four days. 
At such a period the plants, if mature and vigorous, will bear a 
large number of flower buds, which open in the evening after sunset 
and close with the approach of strong morning light, never again 
to open. The following night other buds will bloom, and so on 

262 



DECORATIVE VALUE OF CACTI. 



19 



until in a few days all will have passed the blooming period, which, 
after an interval of time, will recur. In our northern conservato- 
ries there are usually three or four such periods during the summer 
season, averaging about four or five weeks apart. On these occa- 
sions the display of large white flowers in abundance in the moon- 
light is a wonderful sight. Most of the species of Echinocereus pro- 
duce comparatively large showy flowers in a crown about the ends 
of the branches. They are very attractive in their highly colored 
(yellow, orange, red, and purple) waxy flowers, but they do not 
respond so readily to cultivation as many others, especially in 
greenhouses. Some species of Ecliinopsis also produce flowers in 
abundance for a period of a few days. These are trumpet shaped, 
upright, about 8 inches long, forming a crown about the top of the 
plant. They range in color from pure wliite to pale yellow or rosy 
pink. 

The chief attractiveness and beauty in cacti as a group 1 is the 
remarkable symmetry of growth in the individual plants. The colum- 
nar, and most of the genera of smaller cylindrical or globular forms, 
have clean-cut, longitudinal, paraUel angles, ribs, or wings, and located 
on them at regular intervals are the buds, or pulvini, which bear 
the spines and flowers, and from which side branches may be devel- 
oped. The coloring of the epidermis of the plant is frequently 
very attractive. YVhile in most species this color is some shade 
of green, many specimens are coated over to a greater or lesser 
extent with white or bluish glaucousness. In some species the 
surface is dotted over with very small bunches of velvety white 
hair, as in Echinocactus my rio stigma, E. ornatus, and E. capricornus. 
Other species are mottled with purple, which in the young growths 
of E. ingens is arranged in transverse bands, alternating with bright 
green. The coloring of the spines, too, is often exceedingly attrac- 
tive, especially in the younger growths. It ranges from pure white 
to amber, yellow, red, and black. Frequently some of these colors 
are combined on one spine in either longitudinal stripes or transverse 
bands, and the perfectly uniform variegation is very striking. The 
form, structure, and arrangement of the spines are in most instances 
remarkable and show a wonderful adherence to a definite plan of 
symmetrical arrangement. In certain species some of the spines 
have a structure of soft and hard transverse layers from base to tip, 
giving an uneven though uniformly wavy surface much like that of 
a goat's horn. The larger number of spines are straight or only 
slightly curved; others have the end curved in the form of a fishhook. 
Nearly all of them are rather stiff, but some are soft and featherlike 

1 See Safford, W. E., " Caetacese of Northeastern and Central Mexico, Together with a Synopsis of the 
Principal Mexican Genera," in Annual Report, Smithsonian Institution, 1908, pp. 525-563, in which are 
illustrations of many species of Cactaceae. 
262 



20 



ORNAMENTAL CACTI. 



in structure and others are thin, flat, paperlike, and flexible. Again, 
in some species the spines are entirely absent. Mamillaria (Pis. I 
and II) and some groups of Echinocactus have all the variations of 
characters already described, but differ materially in body structure. 
In them the ribs or angles have entirely disappeared and are repre- 
sented by rows of tubercles or mammae, each bearing at its summit 
a cluster of spines. In this group the tubercles are not arranged in 
longitudinal rows, but are geometrically tesselated over the plant sur- 
face, so arranged as to form spirals imming in both directions about 
the plant. 

A remarkable and interesting feature is the regularity in number 
with which these spiral rows appear. As a rule they fall into the 
numbers 5, 8, 13, 21, 34, 55, and possibly higher numbers. For 
instance, if it is found that there are 13 parallel rows of tubercles 
running obliquely around the plant in one direction, there will be 
either 8 or 21 such parallel rows running obliquely around it in the 
other direction. Whatever the number of rows counted in one direc- 
tion, the number counted in the opposite direction will be the one 
either preceding or following it in the series. Exceptions to this rule 
are rare, and when one is noted the numbers are usually found to be 
the doubles of two adjacent numbers in the above series, as 10, 16, 
26, 42, and so on. Another interesting fact is that each number in 
the series is the sum of the two immediately preceding it. 

Symmetry is the greatest attraction in this group of plants. Mon- 
strosities are, however, not infrequent in the family, usually assuming 
a cristate or cockscomb form of growth. These forms are so odd in 
appearance that they are frequently sought after, and it is not 
uncommon to find them represented in the collections of amateurs. 
Their very grotesqueness commends them to the consideration of 
collectors. 

SINGLE PLANT DISPLAYS. 

Each individual plant has an attraction of its own. (Pis. XI, XII, 
and XIII.) Whether it be the symmetrical order of its trunk, its 
color, its versicolored or versiform spines, or a combination of all 
these features, supplemented in its proper seasons by the production 
of flowers and fruits, each normal, healthy plant is well worthy of 
consideration as an individual specimen. Their adaptability is such 
as to commend them for situations where many other plants could 
not exist. They do not require frequent repotting and replenishing 
of soil, and subsist best on a miiiimum of water, so that if necessarily 
neglected for a time they do not materially suffer. A single plant is 
well worth the little trouble required for its keeping. It occupies a 
very small amount of space in comparison to its weight, which is an 
advantage in many instances. 

262 



Bui. 262, Bureau of Plant Industry, U. S. Dept. of Agriculture. PLATE XI. 




Bui. 262, Bureau of Plant Industry, U. S. Dept. of Agriculture. 



Plate XII. 




Bui. 262, Bureau of Plant Industry, U. S. Dept. of Agriculture. 



Plate XIII. 





Bui. 262, Bureau of Plant Industry, U. S. Dept. of Agriculture. 



Plate XIV. 




DECORATIVE VALUE OF CACTI. 



21 



A pretty and interesting display may be had by arranging the 
plants in groups on benches, on window sills, or on bracket shelves on 
either side 6f a window. Pots of individual plants of various sizes 
lend themselves very readily to artistic arrangement. In any banking 
elTect the larger and taller ones should be placed in the background, 
and the rest graded down to the front according to the size of the 
plants. Should the plants be too uniform in size for such arrange- 
ment, those in the background may be elevated on inverted pots or 
blocks of wood of suitable height. 

GROUPINGS. 

Pleasing effects may be obtained by placing a number of plants in 
one pot or small box. For this purpose it is necessary to choose small 
plants, preferably the low-growing globular or short, cylindrical forms 
of Mamillaria and Echinocactus. With a little care in the selection 
of perfectly symmetrical plants with well-developed spines, and some 
taste in arrangement, a compact group may be built up which will 
make an excellent ornament for the table or window and can easily 
be moved to any place desired. In the diversity of designs which may 
be followed there is a wide range of possibilities, ornamental pots or 
boxes lending an artistic touch to the composition. 

PLANTINGS IN OPEN GROUND. 

Cactus roots naturally penetrate deep into the soil, and at the same 
time some of them spread widely from the plant stem. This tendency 
is necessarily limited in potted plants, and the plant does not receive 
the nourishment or water that it should have; hence it is always 
better to place them in the open ground if possible. In the Northern 
States it is necessary that the plants be protected from frost in winter. 
In such localities a room in a greenhouse may be set aside for this 
group of plants, and beds made in the native earth to receive them. 
Here they may be placed close together, as they shade one another 
very little and do not have the abundant foliage of other plants. The 
roots may intermingle, but to no greatly detrimental extent, since the 
main feeding roots penetrate deep down into the soil. Furthermore, 
cactus plants need comparatively little nourishment, and it would 
require a long period of time to exhaust the soil. An effective ar- 
rangement is to build up rocks and soil, leaving the surface more or 
less covered with rocks, making a genuine rockery. (PI. XVII.) This 
treatment lends a natural aspect to the surroundings and furthermore 
adds a greater degree of drainage, so necessary to cacti at all times. 

Cacti may be used as good decorative plants in outdoor beds, 
planted either temporarily or permanently. (PI. XVI.) Where one 
has a number of individual potted plants that have to be housed for 

262 



22 



ORNAMENTAL CACTI. 



protection in the winter season, it is always desirable that they be 
placed in the open during the summer months. They should be taken 
out as soon as all danger from frost is past and left till danger from 
frost threatens in the fall. The beds should be either high or on a 
sloping surface, to insure thorough drainage about the plants. With 
such plants it is better to leave them potted and plunge the pots into 
the soil. (Pis. XIV and XV.) Plants thus exposed to the sunshine 
and rain during the summer months will do far better than those kept 
indoors and given house treatment. A judicious arranging of the 
plants in such beds will have an attractive and pleasing effect. Where 
a large number of individuals of a few species are available, some 
artistic designs may be worked out in these summer beds. 

In the warmer southern or southwestern portions of our country a 
very large number of cacti will thrive out of doors the year round. 
In such localities the possibilities for bed planting have a much wider 
range. More area may be given to them there than would be neces- 
sary in the conservatories of the North. They will require greater 
space, because plants that grow in the open thrive much better than 
potted ones and consequently branch and spread over a greater area. 
In such localities, with plenty of room, it is possible to produce 
decidedly realistic landscape effects. Especially is this true in parks 
(Pis. XVI and XVII) , where the semiarid character of the native home 
of the cacti may be reproduced with wonderful accuracy. Winding 
paths may be laid out through the tract and the borders planted in 
irregular groups, so that the effect will change as one passes along any 
of the w^alks. 



The following list contains the names of most of the cacti now in 
cultivation in the United States. Many other forms are to be found 
in collections but are not at all common. They are grouped with 
reference to their habits of growth. Measurements, where given, refer 
to mature plants and are only approximate. The list, arranged as 
it is with reference to size, will serve as a guide to prospective pur- 
chasers in dealing with collectors and traders. 



CULTIVATED FORMS OF CACTI. 



Columnar Forms of Cacti. 



Tall— over 6 feet in height. 



Cephalocereus: 



Cereus — Contd. 
euphorbioides. 
forbesii. 
geometrizans. 
giganteus. 
hankeanus. 
hildmannianus. 
jamacaru. 
macrogonus. 
marginatus. 
pecten-abori gi num , 



Cereus — Contd. 



Pilocereus— Contd. 



Cereus: 



chrysomalus. 
senilis. 



azureus. 

baumannii. 

chiotilla. 

coerulescens. 

co'.umnaris. 

dumortieri. 

eburneus. 



peruvianus. 

pringlei. 

serpentinus. 

stellatus. 

thurberi. 

weberi. 



hoppenstedtii. 

houlletii. 

lanuginosus. 

polylophus. 

russelianus. 



cometes. 
exerens. 
fulviceps. 



Opuntia: 

cereiformis. 
Pilocereus: 

chrysacanthus. 



schottii. 
strictus. 



262 



Bui. 262, Bureau of Plant Industry, U. S. Dept. of Agriculture. PLATE XV. 




Bui. 262, Bureau of Plant Industry, U. S. Dept. of Agriculture. 



Plate XVI. 




Bui. 262, Bureau of Plant Industry, U. S. Dept. of Agriculture. 



Plate XVII. 




Bui. 262, Bureau of Plant Industry, U. S. Dept. of Agriculture. 



Plate XVIII. 




CULTIVATED FORMS OF CACTI. 



23 



Columnar Fokms of Cacti— Continued. 





Lower— from 1 to 6 feet in height. 




Cereus: 


Cereus — Contd. 


Ecbinocactus: 


Ecbinocactus— Contd. 


candicans. 


spacbianus. 


cylindraceus. 


pilosus. 


emoryi. 


speciosus. 


ingens. (PI. XVIII.) 


recurvus. 


eruca. 


tbelegonus. 


johnsonii. 


Ecbinopsis: 


gummosus. 




ornatus. 


eyriesii. 


mamillatus. 




peninsulae. 






Short — less than 1 foot in height. 




Echinocactus: 


Ecbinocereus: 


E cbinocereus — Contd. 


Mamillaria — Contd. 


anfractuosus. 


acifer. 


pboeniceus. 


erecta. 


beguinii. 


berlandieri. 


procumbens. 


eriacantba. 


bicolor. 


cblorantbus. 


rigidissimus. 


grabamii. 


capricornus. 


cinerascens. 


roemeri. 


gracilis. 


gibbosus. 


conglomeratus. 


stramineus. 


balei. 


intertextus. 


ctenoides. 


viridiflorus. 


leona. 


krausei. 


dasyacanthus. 


Mamillaria: 


macromeris. 


lenningbauseii. 


dubius. 


carnea. 


microthele. 


leucacantbus. 


engelmannii. 


clava. 


radiosa. 


longibamatus. 


fendleri. 


conoidea. 


rapbidacantba. 


scbeeri. 


knippelianus. 


cornifera. 


roseana. 


uncinatus. 


mojavensis. 


dolicbocentra. 


setispina. 


wbipplei. 


paucispinus. 


elegans. 


spinosissima. 




pectinatus. 


elongata. 


strobiliformis. 




Globose Forms of Cacti. 






Large— more than 1 foot in diameter. 




Ecbinocactus: 


Ecbinocactus — Contd. 


E cbinocactus — Contd . 


Ecbinocactus — Contd. 


electracantbus. 


grusonii. 


longibamatus. 


wislizeni. 


emoryi. 


ingens. 








Medium— from 3 inche 


s to 1 foot in diameter. 




Ariocarpus: 


Ecbinocactus— Contd. 


Ecbinopsis: 


Mamillaria — Contd. 


fissuratus. 


borizontbalonius. 


gemmata. 


melanocentra. 


retusus. 


lophotbele. 


multiplex. 


mutabilis. 


Ecbinocactus: 


multicostatus. 


nigricans. 


radiosa. 


albatus. 


myriostigma. 


oxygona. 


robustispina. 


capricornus. 


polycepbalus. 


Leuchtenbergia: 


scbeeri. 


coptonogonus. 


robustus. 


principis. 


seitziana. 


corniger. 


setispinus. 


Mamillaria: 


Melocactus: 


crispatus. 


texensis. 


celsiana. 


communis. 


beterocbromus. 


unguispinus. 


gigantea. 


ferox. 


bexaedrophorus. 




beeseana. 






Small — less than 3 inches in diameter. 




Ariocarpus: 


Lopbopbora: 


Mamillaria— Contd. 


Mamillaria — Contd . 


kotscbubeyanus. 


lewLnii. 


formosa. 


pusilla. 


Ecbinocactus: 


williamsii. 


gummifera. 


radians. 


denudatus. 


Mamillaria: 


heyderi. 


recurvata. 


bumilis. 


angularis. 


lasiacantba. 


rbodantha. 


intertextus. 


bicolor. 


lesaunieri. 


scbelbasei. 


macdowellii. 


bocasana. 


longimamma. 


sempervivi. 


mammulosus. 


Candida. 


meiacantba. 


senilis. 


minusculus. 


caput-medusae. 


micromeris. 


spbaerica. 


ottonis. 


carretii. 


missouriensis. 


uncinata. 


scnickendantzn. 


centricirrba. 


parkinsonii. 


wildii. 


scbiiinzkyanus. 


decipiens. 


perbella. 


zepbyrantboides. 


simpsoni. 


dioica. 


pbellosperma. 


Pelecypbora: 


submammulosua. 


elegans. 


plumosa. 


aselliformis. 


tabularis. 


elepbantidens. 


polyedra. 


pectinata. 



turbiniformis. 
262 



24 



Opuntia: 

brasillensis. 

chlorotricha. 

engelmannii. 

Opuntia: 

camanchica. 
curassavica. 



Opuntia: 
arenaria. 
basilaris. 
decuinbens. 



Opuntia: 

acanthocarpa. 
arbuscula. 



Opuntia: 



bemardina. 
cholla. 



Opuntia: 
clava. 
davisii. 



Peireskia: 
aculeata. 
godseffiana. 

Peireskia: 
amapola. 
bleo. 



Cereus: 

baxaniensis. 
bonplandii. 
grandiflorus. 
hamatus. 



Phyllocactus: 
ackermannii. 
acuminatus. 
anguliger. 

Cereus: 

flagelliformis. 

Kpipbyllum: 
gaertnerl, 

russellianum. 
truncatum. 
2G2 



ORNAMENTAL CACTI. 

PLATYOPUNTIAS AND NOPALEAS. 

Tall forms— over 6 feet in height. 



Opuntia— Contd. 
ficus indica. 
leucotricha. 
puberula. 



Opuntia — Contd. 
robusta. 
tomentosa. 
tuna. 



Nopalea: 
aubcri. 
dejecta. 



Medium forms- 
Contd. 



Opuntia 

mierodasys. 
monacantba. 

Low or decumbent forms- 
Opuntia— Contd. 
fragilis. 
missouriensis. 
pes-corvi. 

Cylendropuntias. 

Tall forms — over 6 feet in height. 
Opuntia— Contd. Opuntia— Contd 



2 to 6 feet in height. 
Opuntia— Contd. 

monacantha variegata 
rafLnesquei. 

-less than 2 feet in height. 
Opuntia— Contd. 
procumbens. 
rutila. 
strigilis. 



Nopalsa: 

cceclneilifera. 



Opuntia — Contd. 
ursina. 
vulgaris. 



bigelowii. 
fulgida. 



imbricata. 



Medium forms— 1 to 6 feet in height. 
Opuntia— Contd. Opuntia — Contd. 

eohinocarpa. salmi ana. 

leptocauUs. subulata. 

Low or prostrate forms— less than 1 foot in height. 
Opuntia — Contd. Opuntia — Contd. 

diademata. grahamii. 
emoryi. parryi. 

Foliage-Bearing Cacti. 
Climbing or clambering forms. 

Peireskiopsis: 
brandegeei. 
spatbulata. 
Shrubs or small trees. 

Peireskia — Contd. 
nicoyana. 

Climbing, Night-Blooming Forms of Cereus. 
Cereus— Contd. Cereus— Contd. 

irradians. nycticalus. 
macdonaldiae. ocamponis. 
martini. setaoeus. 

Plants Native to Moist Tropical T.egicns. 

Tcrrestri'il. 

Pbyllocactus— Contd. Pbyllocactus— Contd. 



Opuntia— Contd. 
prolifera. 



Opuntia — Contd . 
versicolor, 
wbipplei. 



Opuntia— Contd. 
scbottii. 



crenatus. 
grandis. 



ITariota: 

salicornioides. 
Rhipsalis: 

ancepa. 



hookeri. 
phyllantboidf 



Epiphytic. 



Ilhipsalis— Contd. 
conferta. 
,'Tandiflora. 
bouHitniia. 



Cereus— Contd. 
spinuLsus. 
tortuosus. 
triangularis. 



Phyllocactus - Contd. 
stenope talus, 
strictus. 



Pvbip;ali3— Contd. 
paradoxa. 
pentaptera. 
rhombea. 



mesembryantliemoides. saglionis. 



O 



13 



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